hort crops

Question 1

what is in the cucurbitacaea family

Answer 1

cucumbers, watermelon, squash and pumpkin

Question 2

what are root crop common factors

Answer 2

Deep soil preparation

most are longer-term annuals (over 120 days)

mechandised harvest for commercial growers

postharvest systems specific to each group

Question 3

give a description of kumara production factors

Answer 3

harvest swollen roots

vegetative parts are frost tender

cuttings are planted

tubers laid for cutting propagation in aug/sept

deep soil preparation is crucial - well-drained sandy loam

harvest the same as potatoes

90%of crop in Dargaville

Question 4

what is ipomoea batatas

Answer 4

kumara

Question 5

what is involved with kumara crop health

Answer 5

viruses are a major issue in yeild reduction

pest issues such as Aphids, hawk moth and potato psylid

Diseases: black rot soft rot

Question 6

give points of potato production establishment

Answer 6

harvest plant tubers

vegetative parts are frost tender

“seed” tubers planted

PH can affect scab incidence

Maincrop planted October - January

Question 7

what involved with potato crop health

Answer 7

potato viruses major issue - seed certification programme to maintain clean stock

pest issues: potato tuber moth, aphids, potato psyllid

diseases: early blight, powdery scab, late blight

Question 8

what are the botanical characteristics for onion production

Answer 8

biennial (but grown commercially as an annual unless seed crop

roots very shallow

terminal inflorescence developed after vernalisation; insect-pollinated

bulb harvested - swollen scales, various shapes

Question 9

industry facts for onion

Answer 9

main exports Uk, Asia

the highest value of vegetable export

Export market quality-focused and there is potential for quality deterioration to occur on the long sea journey to UK

Question 10

production requirements for onion

Answer 10

seeded in NZ winter- don’t sow too early

tolerant to frost.

weed control is a big issue

dry bulbs production most challenging

early spring and fresh main crop sown apr may

main crop dry bulbs sown august - sept

grown in rotation 1 year in every 3 or 4

Question 11

Key site factors for onion

Answer 11

good drainage

raised beds

planting material either: seeds, sets, transplants

population density can increase yield but decrease marketable year

Question 12

pest and diseases for onions

Answer 12

Pests: onion thrips, aphids, onion maggots

disease: botrytis, white rot, downy mildew

Question 13

post-production - preharvest/ post-harvest - operations onion

Answer 13

leaf condition an indicator of the maturity and general state of the bulb

onions to be stored must mature fully before harvest

when 70-80% of leaves just above the bulb fall over in the whole crop it harvests time

tops and roots cut off by hand or mechanical means

Question 14

how are onions harested

Answer 14

bulbs lifted from soil to dry

then lifted by hand or machine into bins

aim to minimise the time crop lies on the ground to cure, exposed to the weather,

drying can be done artificially

Question 15

market criteria for onions

Answer 15

sufficiently dry for the intended use

free from moisture-free from foreign smell or taste

stems twisted or clean cut. no longer than 4 cm

onions must be intact with outer skin included

free from frost damage

Question 16

problems with storing onions and how to remedy

Answer 16

deterioration in quality due to decay and shooting

reduced by high temp curing and reduced relative humidity storage

onions best stored at 0 degrees and separately to prevent odour transfer

they can last 3 weeks post-harvest or 1-8 months at optimum temperature

Question 17

cucumber production

Answer 17

harvest fruit of the plant

produce male and female flowers

some varieties are mostly parthenogenic (no polination)

new varieties are mostly gynaecious

vigorous growers, training essential

Harvested relatively immature

Question 18

cucumber establishment

Answer 18

a strong taproot characterises the root system and may reach 1 meter deep

the root system is extensive but rather shallow

growth is in two stages 1. upright growth until 5-6 nodes stage 2. vining, side shoots begin to emerge while the main leader continues to grow. plant flops over. each flower/fruit is borne on its own stem attached to the main stem

Question 19

describe the flower and fruits of cucumbers

Answer 19

different flower types male, female, hermaphrodite

flowers require pollination via bees

some plants only produce female flowers and need a pollinizer but are very productive

Question 20

how does pollination work for cucumbers

Answer 20

each cucumber flower is open only one day.

10-20 visits per flower is needed

bees should be brought in at 20% flower burst

not to early or too late

pollination in gynoecious female flowercrops are blended with monoecious seed at a ratio of 88%- 12%

Question 21

requirements for growth of cucumbers

Answer 21

high temperature, humidity, and light intensity and with an uninterrupted supply of nutrients.

need frequent pruning of main stem and laterals.

too much fruit can result in the plant being exhausted, abort fruit

cucumbers are sensitive to unfavourable conditions and slight stress affects their growth and production

air temp is the main environmental component larger the variation the better 19-20 night 20-22 day temp

Question 22

cucumber health problems

Answer 22

damping-off of seedlings

black root rot

powdery mildew

fruit: scab, botrytis

Question 23

lettuce production requirements

Answer 23

nutrient demand high especially nitrogen

key plant health issues with lettuce aphid ( biggest problem), big vein disease in cool climates

warm soils

free draining

usually transplants